Conventional monitoring systems and devices that record and store one or several scenes commonly contain a plurality of cameras that provide image data and, if a microphone is present, audio data of the scenes. For example, FIG. 1 shows a plurality of cameras 30 that record the goings-on at a location frequented by many people. If analog cameras are used to record the images and/or sound, the cameras 30 are each connected to an analog-to-digital converter 22, with a coder 24 for data compression being arranged downstream. If a digital camera is used, the cameras 30 are each directly connected to the coder 24. Each camera 30, optional A/D converter 22 and coder 24 together form one channel of a multitude of n channels, with n being a whole number greater than or equal to 2. To this effect, the camera, A/D converter and coder are controlled and actuated by a controller. The compressed image and/or audio data of the n channels are fed via a network 40, for example a local network (LAN, Local Area Network), into a central storage device that is actuated by a controller for the management of the data fed into it and that has a multitude of hard drives to store the data. The overall capacity of the storage device 50 lies within the range of several terabytes for about thirty channels.
In known monitoring systems, the controller allocated to the storage device provides for a relatively efficient utilization of the available storage space, with provisions being made to a limited degree for loss of data in the event of a defect or malfunctioning of smaller storage areas. For example, if one of the hard drives fails, the redundant storage management of the controller is capable of compensating the attendant data loss at least partially. But at a minimum, the loss of a large portion of the data that were stored so far can be prevented, and the intended operation of the storage device can be maintained. However, preventing the loss of the data stored so far and maintaining the operation of the storage device is possible only after carrying out a reorganization of the storage device by the controller itself, which results in no or very few data being able to be stored due to the increased load. As far as the avoidance of any loss of data and maintaining the intended operation are concerned, the storage device is subject to very narrow limits. If, for example, two hard drives of the storage device fail, the controller can no longer carry out a successful reorganization of the storage device due to the amount of data that are no longer accessible by it.
In addition to that, the network 40 is susceptible to defects as well. The network defects may result in image and/or audio data, which was fed error-free into the network, appearing at the network's output delayed, distorted or not at all. Thus, a system for processing, monitoring and storing multi-channel image and/or audio data is sought that exhibits increased operational reliability as compared to known image processing systems.